kivy: fix settings layout

gui/kivy/main.kv

@@ -322,7 +322,7 @@
     orientation: 'vertical'
     title: ''
     description: ''
-    size_hint: 1, None
+    size_hint: 1, 1
     Label:
         id: title
         text: self.parent.title
@@ -333,7 +333,7 @@
     Label:
         text: self.parent.description
         size_hint: 1, 1
-        text_size: self.size
+        text_size: self.width, None
         color: 0.8, 0.8, 0.8, 1
         halign: 'left'
 

gui/kivy/main_window.py

@@ -808,7 +808,7 @@ class ElectrumWindow(App):
         self.protected(self._change_password, ())
 
     def _change_password(self, old_password):
-        if old_password:
+        if self.wallet.use_encryption:
             try:
                 self.wallet.check_password(old_password)
             except InvalidPassword:

gui/kivy/uix/ui_screens/settings.kv

@@ -13,7 +13,7 @@ Popup:
         CardSeparator
         SettingsItem:
             title: _('Denomination') + ' (' + app.base_unit + ')'
-            description: "Base unit for Bitcoin amounts."
+            description: _("Base unit for Bitcoin amounts.")
             on_release:
                 app._rotate_bu()
                 self.title = _('Denomination') + ' (' + app.base_unit + ')'